Gearing Question c-500!

[Dentz]

My c-500 top shaft turns one revolution..the prop turns to 10oclock....It's 10%underdrive I would guess? What would 10% over do if I am running 81GPS at 5500 now! Last year.....at 3600 to 5500 I run from 41 to to 81...And the last time out with out GPS....I rejetted and it ran 6000...so I am guessing high 80's with a 12x17 three blade....? A friend has a 12x17 two blade...What will the same size 2 blade change...I am assuming alot more R's more top end....will the boat lift the nose more with the 2 blade.../
Thnaks...might be looking for gears and props...Help!

[superdave013]

Like I said in my pM. One change at a time.
Your first one needs to be replacing that nybral prop that you now have.
Get a safe prop on it before it's to late.
Just my .02

[Rexone]

I'll ditto that Dentz. I didn't realize you had a Nibral prop and not steel when you PM'ed me. Doesn't belong on a turbo deal, asking for trouble. And the blade flex is huge, you'll never achieve proper performance either.

[V-Drive Tom]

DENTZ, You are at 10% overdrive now. When you turned your prop around one revolution it had to go past 12 oclock to get to ten oclock. So it went one time around PLUS that amount.
NO v-drive boat is ever set up so that it is underdriving the propeller.
You need a good 16 pitch 2-blade to get the best speed you can get out of the boat.
When you get tired of putting up with the 2-blade you will want a 3-blade (16 pitch) that will be perfectly smooth-pull harder and only go about 5to6 mph slower.
Check out what I am saying about the prop overdrive.
Then call me for a propeller, Your boat is only a credit card number away from working properly.:D :cool: TOM..

[mickeyfinn]

Hey Tom,
Don't some of the newer Turbine applications underdrive their props? Some of those guys turn 12,000-14000 rpms on the output of the turbine.

[schiada96]

Change the prop or your looking at a big repair bill, and maybe a sunk boat